KVM: Drop hack that "manually" informs lockdep of kvm->lock vs. vcpu->mutex

Now that KVM takes vcpu->mutex inside kvm->lock when creating a vCPU, drop
the hack to manually inform lockdep of the kvm->lock => vcpu->mutex
ordering.

This effectively reverts commit 42a90008 ("KVM: Ensure lockdep knows
about kvm->lock vs. vcpu->mutex ordering rule").

Cc: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241009150455.1057573-7-seanjc@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>